3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item Spatial clustering of HIV/AIDS mortality events in rural South Africa population between 2000-2006(2010-04-16T11:58:31Z) Namosha, Elias EBackground: Cluster detection analysis could be an appropriate approach to identify critical AIDS mortality locations for public health intervention. Methods: GIS and Kulldorff’s spatial scan statistic was used to investigate statistically significant AIDS mortality clusters (p 0.05). SaTScan was used to perform the spatial analysis scanning while MapInfo was used as a visualizing tool. Mortality data between 2000- 2006 were analyzed. Results: AIDS exhibit strong spatial clustering tendencies as measured by the Kulldorff’s spatial scan statistic method. Conclusion: Further work is needed to understand the underlying mechanisms responsible for the spatial clustering.Item Mortality and violence in Agincourt, a rural area of South Africa(2009-11-17T12:53:28Z) Mosiane, Malerato Adelaide NthamaneViolence is a hidden problem in most communities, yet it is among the leading causes of death and non-fatal injury worldwide. It is an essential public health issue for every country and needs to be addressed as a matter of priority. While rural areas of South Africa are believed to be safer than urban areas, they are not necessarily safe per se. The main objective of this study is to examine the burden of fatal violent injuries on a rural South African community. The violent deaths data used in this report were collected through a verbal autopsy (VA) process during the period 1992 to 2000 in Agincourt, Bushbuckridge, a rural area in the north-eastern part of South Africa with a population of about 69 000 people. Person-years data for the same period, obtained from the Agincourt Health and Demographic Surveillance System (AHDSS), were used for the denominator in the computation of rates. Violence accounted for 5.9% (170/2 859) of deaths from all causes in the Agincourt area between 1992 and 2000. Of the 170 violent deaths, 68.2% were due to assault while the remaining 31.8% were suicides. The proportion of violent deaths, as proportion of deaths from all causes, is highest in the 15–19 year age group (20.9%, compared to 1.0% amongst those under the age of 15 years and 2.0% among those 60 years and older). The small number of victims in each age group results in wide confidence intervals. The violent deaths proportion, as a proportion of deaths from all causes, is higher in males (9%) than in females (2.3%). Violence levels appear to be higher among South Africans than among self-settled former Mozambicans, though the observed difference between these two populations is not statistically significant. However, a statistically significant difference is found between levels of death due to assault among migrants and permanent residents. To address this situation, violence prevention strategies and programmes need to be put in place to reduce violence. However, more research is required in order to identify more risk factors associated with violent behaviour, to study the identified risk factors, and to inform the development of these programmes.Item Clustering of mortality among children under five years due to malaria at the Ifakara demographic surveillance site in Tanzania(2009-04-28T13:20:00Z) Kamara, Mohamed KobloABSTRACT Introduction Under-five mortality is still a major cause of concern in Sub Saharan Africa and among the highest in the world. This is also exacerbated by the high prevalence and episodes of malaria in this age group, which accounts for 90% of all under-five deaths estimated in the region annually. The effect of detecting clustering of all cause and cause specific mortality and underlying factors is crucial for timely public health interventions. This is especially important for health authorities in Tanzania where under-five malaria attributable deaths accounts for 45% of the annual estimated mortality of 100, 000. Study objectives To estimate under-five mortality and analyze clustering of all cause and malaria specific mortality among under five children in Ifakara Demographic Surveillance System from 2002-2005. Methods Data from the Ifakara Health Research and Development Centre (IHRDC) were obtained for all under-five children who lived in 25 villages in the DSS from 2002 – 2005. Analyses for all cause and malaria cause specific under-five mortality were done using data collected from the DSS and verbal autopsy systems. Annual all cause and malaria specific mortality rates were calculated by dividing number of deaths and person years observed. Clustering of deaths for all cause and cause specific (malaria) in the 25 villages were analyzed using SaTScanTM version 7.0 software. A Poisson model was used to detect clusters with high rates in space and in space-time. Household assets and characteristics were used to construct a wealth index using Principal component analysis (PCA) in StataTM version9. The index was used to group households into five equal groups from poorest to least poor. Results Overall infants’ mortality was sixty-three times higher (326 per 1,000 person years) compared to children (5.1 per 1,000 person years) and with mortality rates between girls and boys were very similar, (15.8 and 14.8 per 1,000 person years). Year of death and place of death (village) were found to be significantly associated with malaria deaths. However, socio-economic status of parents in households where deaths occurred was not associated to malaria deaths in the DSS. A number of statistically significant clusters of all cause and cause specific malaria deaths were identified in several locations in the DSS. The located clusters imply that villages within the clusters have an elevated risk of under-five deaths. A space-time cluster of four villages with radius of 15.91 km was discovered with the highest risk (RR 2.71; P-value 0.020) of malaria deaths in 2004. Conclusion These findings demonstrate that there is non-random clustering of both all cause and malaria cause specific mortality in the study area. The high infant mortality results also suggest a careful examination of the data collection procedures in the DSS and require further studies to understand this pattern of mortality among the under-five population. Appropriate health interventions aimed at reducing burden of malaria should be strengthened in this part of rural Tanzania. There is need to replicate this study to other areas in the country.Item Risk factors for mortality in patients with invasive pneumococcal disease in South Africa(2008-07-17T08:37:12Z) Nyasulu, Peter SuwirakwendaABSTRACT Introduction Invasive pneumococcal disease (IPD) is an important cause of morbidity and mortality in many parts of the world. It is estimated that pneumococcal disease causes more than one million-childhood deaths every year and the burden of disease is greater in developing countries. The main aim of this study was to analyze risk factors associated with mortality in invasive pneumococcal disease in all ages in South Africa. Materials and Methods We performed an analytical cross-sectional analysis of secondary data from national population-based surveillance for invasive Streptococcus pneumoniae infection in South Africa. The study period was 1 January 2003 to 31 December 2005, and the mortality analysis used a subset of laboratory-confirmed cases who had a completed case report form and available mortality data. Multiple logistic regression models were constructed to identify risk factors significantly associated with the increased risk of death in patients with invasive pneumococcal disease. Separate models were used to evaluate risk factors for death in patients with meningitis and those with other IPD. Results There were 1154 (24%) cases of Streptococcus pneumoniae meningitis and 3736 (76%) cases of other invasive disease. The overall case fatality rate was 1360/4890 (27.8%) of which 911 (67%) patients died within 2 days of admission and 449 (33%) died between 2 days and 30 days of admission. Variables associated with mortality in a logistic regression analysis of all IPD patients included meningitis (OR 2.8, CI 1.9 – 3.9, P=<0.001), HIV-infection (OR 2.8, CI 1.6 – 4.6, P=<0.001), acute severe illness measured by Pitt bacteraemia score >=4 (OR 4.7, CI 2.8 – 7.7, P=<0.001) and prior antibiotic use within 2 months before first positive culture (OR 2.1, CI 1.4 – 3.1, P=<0.001). In addition to this children less than 1 year and adults ≥45 years were more likely to die compared to other age groups. Patients from Western Cape Province were significantly less likely to die (OR 0.27, CI 0.15 – 0.50, P=<0.001) compared to other provinces. Amongst HIV-positive patients severe immunosuppression (low CD4+ count) was a risk factor for death. Risk factors for death were similar in patients with other IPD and meningitis except for HIV which was associated with death in the meningitis group but not in the other IPD group. Antibiotic resistance and vaccine-serotype disease were not associated with increased risk of death. Discussion and Conclusions IPD is associated with a high mortality in South Africa. Our findings of increased risk of death in HIV-positive patients especially those with low CD4+ count are of importance given the high prevalence of HIV amongst patients with IPD. Introduction of the pneumococcal conjugate vaccine as part of the national expanded program for immunization (EPI) and ensuring access to antiretroviral therapy for HIV-positive patients where indicated should be prioritized.Item The impact of HIV/AIDS on mortality at a South African platinum mine(2008-05-14T11:37:50Z) Dowdeswell, Robert JosephABSTRACT Background: There is a paucity of empirical data on the impact of HIV/AIDS on mortality in the mining industry in the pre-ART era. Such data will provide a baseline against which the efficacy of antiretroviral treatment can be measured into the future. Objectives: To measure all-cause mortality in a population of platinum miners between 1992 and 2002, the impact of HIV/AIDS on mortality in this group and to determine the pattern of other cause-specific mortality. Methods: This was a primary analysis of mortality in an open cohort of male semi- and unskilled workers at a platinum mine. Using Poisson regression, all-cause, HIV/AIDSrelated and other cause-specific mortality rates and rate ratios were calculated by age and calendar year. Results: There were 1986 deaths in the cohort of 29954 subjects who contributed 200657 person years of follow up over the 11 year period of the study. Crude all-cause mortality increased from a base of 5.1 per 1000 person years at risk (pyar) (95% CI 4.2- 6.2) in 1992 to 20.4 per 1000 pyar (95% CI 18.3-22.8) in 2002. Age-adjusted all-cause mortality increased more than three-fold from 1992 to 2002 (RR 3.2, 95% CI 2.5-4.0). The excess mortality was attributed to HIV/AIDS-related deaths which increased from 0% in 1992-1994 to 5.1% of total deaths in 1995 and reached 63.3 % of deaths in 2002. Mortality due to other communicable diseases, non-communicable diseases and injuries remained stable throughout the study period. Conclusion: The impact of the HIV/AIDS epidemic on mortality in this group of platinum mine workers has been profound and comparable to that experienced by the general South African population. The data reported here provide a baseline to measure the impact of antiretroviral treatment on the future course of mortality due to the epidemic.Item Ethnicity and Sex Differentials in Infant and Child Mortality in Ghana(2006-11-01T07:17:36Z) Antobam, Samuel KojoSex differentials in infant and child mortality have been reported in many studies. These studies posit that generally the male child has better survival advantage over than the female child. However, none of these studies have examined the role of ethnicity in understanding these differentials. The question then is, to which extent does sex differences in child mortality exist in a society with patrilineal and matrilineal structures. Using Ghana Demographic and Health Survey of 2003 (GDHS, 2003), the study examines the intensity of these differentials by employing indirect method of estimation, and bivariate and multiple regression models, while giving detailed consideration to the differences in biological and behavioural/environmental perspectives as regards child health and nutritional care. It is found that among all the four major ethnic groups in the country, including the matrilineal societies, the male child has higher survival advantage than the female counterpart. The study therefore concludes that ethnicity, be it matrilineal or patrilineal, does not make any difference in sex differentials in child mortality.